Calendars with Olympiad Display and Eclipse Prediction on the Antikythera Mechanism Essay

Calendars with Olympiad display and eclipse prediction on the Antikythera Mechanism
Nature, July 31, 2008
On the Antikythera Mechanism established a highly complex ancient Greek geared mechanism with front and back output dials (1-7). The upper back dial is a 19-year calendar, based on the Metonic cycle, arranged as a five-turn spiral (1, 6, and 8). The lower back dial is a Saros eclipse-prediction dial, arranged as a four-turn spiral of 223 lunar months, with glyphs indicating eclipse predictions (6). Here we add surprising findings concerning these back dials. Though no month names on the Metonic calendar were previously known, we have now identified all 12 months, which are unexpectedly of Corinthian origin. The Corinthian colonies of northwestern Greece or Syracuse in Sicily are leading contenders--the latter suggesting a heritage going back to Archimedes. Calendars with excluded days to regulate month lengths, described in a first century BC source (9), have hitherto been dismissed as implausible (10,11). We demonstrate their existence in the Antikythera calendar, and in the process establish why the Metonic dial has five turns. The upper subsidiary dial is not a 76-year Callippic dial as previously thought (8), but follows the four-year cycle of the Olympiad and its associated Panhellenic Games. Newly identified index letters in each glyph on the Saros dial show that a previous reconstruction needs modification (6). We explore models for generating the unusual glyph distribution, and show how the eclipse times appear to be contradictory. We explain the four turns of the Saros dial in terms of the full moon cycle and the Exeligmos dial as indicating a necessary correction to the predicted eclipse times. The new results on the Metonic calendar, Olympiad dial and eclipse prediction link the cycles of human institutions with the celestial cycles embedded in the Mechanism's gear work.
This extraordinary astronomical mechanism from about 100 BC employed bronze gears to make calculations based on cycles of the Solar System (1,6) (Supplementary Notes 1). Recovered in 1901 by Greek sponge-divers, its corroded remains are now split into 82 fragments--7 larger fragments (A-G) and 75 smaller fragments (1-75) (6). Data, gathered in 2005'[degrees]', included still photography, digital surface imaging (12) and, crucially for this study, microfocus X-ray computed tomography (CT) (6,13) (Figs 1-3)--details are in Supplementary Notes 2 (and at www.antikythera-mechanism.gr).
The main upper back dial is now established as a Metonic calendar (1, 6, and 1) (Figs 1 and 2, Supplementary Box 1). The calendar dial bears inscriptions, only viewable using X-ray CT. We have now identified all 12 months of this calendar (Fig. 2, Supplementary Notes 3), providing conclusive evidence of the regulation of a Greek civil calendar by a Metonic cycle, and clues to the instrument's origin. Whereas the Babylonian calendar followed a Metonic cycle from about 500 BC, it has commonly been assumed that the intercalary months of the numerous lunisolar calendars of the Greek cities were determined arbitrarily-Metonic and Callippic cycles (Supplementary Box 1) only being used by astronomers (14). The month names on the Metonic spiral, however, belong to a regional calendar unassociated with technical astronomy, suggesting that it may have been common for Greek civil calendars to follow the Metonic cycle by about 100 BC.
The inscriptions show that not only the names and order of the months were regulated, but also which years had 13 months, which month was repeated in these years, and which months had 29 or 30 days. The rules are…

engineer who originated the concept of a programmable computer. Considered a "father of the computer” Babbage is credited with inventing the first mechanical computer that eventually led to more complex designs. Parts of his uncompleted mechanisms are on display in the London Science Museum. In 1991, a perfectly functioning difference engine was constructed from Babbage's original plans
b) Programming
Joseph Jacquard, the son of a silk weaver, was born in Lyon in 1752. He inherited his father's…

ou've probably heard people talk about "defense mechanisms," or ways that we protect ourselves from things that we don't want to think about or deal with. The term got its start in psychoanalytic therapy, but it has slowly worked its way into everyday language. Think of the last time you referred to someone as being "in denial" or accused someone of "rationalizing." Both of these examples refer to a type of defense mechanism.
In Sigmund Freud's topographical model of personality, the ego is the…

Popup Calendar for AcroForms
By Thom Parker, WindJack Solutions, Inc.
Currently, there is no really good way to create a general purpose popup calendar for use with Acrobat
Forms, but there are still a couple of ways that it can be done. The calendar presented here is composed
entirely of Acrobat Form Fields and controlled through JavaScript. It was first developed a very long time
ago by Jens Thomsen at Trisect Development in Denmark (www.trisect.dk), who provides it for free. It has
been touched…

The calendar planner: “A tool that is used by every marketer across every industry, world-wide”.
Not all marketing calendars are created equal. Relying on the 1990’s method of using spread sheets or Word documents to manage your marketing activities will not give you the visibility you need in today’s competitive environment. A marketing calendar should be fully integrated with all your marketing activities to give your marketing department one view of the truth. Here are four reasons why:
1. Marketing…

the Chinese New Year (Spring Festival), which is also celebrated in Korea, Vietnam, and other Asian countries. All traditional holidays are scheduled according to the Chinese calendar (except the Qing Ming and Winter Solstice days, falling on the respective Jie qi in the Agricultural calendar).
Date (Chinese Lunar Calendar)
English Name
Chinese Name
Remarks
Last day of lunar year
Chinese New Year Eve
• 除夕
• 大年夜
1st day of 1st Month
Chinese New Year (Spring Festival)
• 農曆新年 / 农历新年
• 春節 / 春节
• 大年初一…

Development on CAEN with Eclipse
This handout describes how to set up CAEN on your personal computer so that you can use the Eclipse
IDE to develop code remotely on CAEN via ssh. As always, we highly recommend developing on CAEN,
either in the labs or remotely, as a very large percentage of student errors in previous terms have been a
result of incompatibilities between platforms.
Note that staff will prioritize helping students with algorithmic questions above those with questions
on Eclipse during office…

calculating sums of money.
The ancient Greek­designed
Antikythera mechanism
, dating between 150 to 100 BC, is the world's oldest analog
computer.
The
Antikythera mechanism
is believed to be the earliest mechanical analog "computer",
according to
Derek J. de Solla Price
.[6]
It was designed to calculate astronomical positions. It
was discovered in 1901 in the
Antikythera wreck
off the Greek island of
Antikythera
, between
Kythera
and
Crete
, and has been dated to …

them from earlier Mesoamerican cultures, the Aztecs carved the calendar stone in 1479 (Smith 253). At the time, the Aztecs lived in a very civilized world filled with amazing architecture, an impressively complex government system, and they also employed intricate systems of writing and calendric systems (Taube 7). The Calendar Stone was made by basalt stone. For the Aztecs, everything was pictorial in nature around this era. The calendar stone depicted different pictograms or Codex Magliabechianoand…

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